SEAMLESS TUBE MATERIALS: ALLOYS AVAILABLE IN COILS AND BARS

Seamless Tube Materials: Alloys Available in Coils and Bars

Seamless tube materials are one of the most critical factors in the design and construction of reliable, safe, and high-performance industrial plants.
Beyond the supply format—coils or bars—it is the choice of alloy that determines tube performance in terms of mechanical strength, chemical compatibility, service life, and regulatory compliance.

For companies operating in highly complex sectors, selecting the right industrial seamless materials means reducing operational risks and optimizing long-term plant performance.

Austenitic Stainless Steels

Among the most widely used seamless tube materials are austenitic stainless steels, supplied both in coils and bars.
Alloys such as AISI 304/304L, AISI 316/316L dual grade, and 6Mo (UNS S31254) offer a proven balance between corrosion resistance, workability, and mechanical reliability.

These materials are commonly used in process and instrumentation applications due to:

• Good corrosion resistance in standard industrial environments;

• Excellent ductility and formability;

• Compatibility with a wide range of fluids and operating conditions.

Duplex and Super-Duplex Steels

When operating conditions become more severe, Duplex and Super-Duplex seamless tubes (Duplex 2205, Super-Duplex SAF 2507) come into play.
These materials combine high mechanical strength with excellent resistance to localized corrosion, making them suitable for aggressive environments and high-pressure applications.

Duplex and Super-Duplex seamless alloys are particularly recommended for:

• Oil & gas and offshore installations;

• Chloride-rich environments;

• Applications requiring high structural performance.

Nickel Alloys for Critical Applications

Nickel alloys such as Hastelloy C276 and Monel 400 represent a key category of industrial seamless materials designed for extreme operating conditions.
These alloys provide structural stability and outstanding chemical resistance even at high temperatures, elevated pressures, and in the presence of highly corrosive media.

Nickel alloys are typically used in:

• Chemical and petrochemical plants;

• High-temperature processes;

• Critical applications with stringent safety requirements.

Nickel-Chromium-Molybdenum Alloys for Highly Aggressive Environments

Advanced seamless tube materials also include Sanicro alloys (Inconel and Incoloy 625/825), a family of high-performance alloys positioned between super-austenitic stainless steels and nickel-based alloys.
These materials are engineered to deliver excellent resistance to localized corrosion and strong mechanical performance in particularly aggressive environments.

Sanicro alloys are used where conventional stainless steels are no longer sufficient, such as in chemical plants, oil & gas installations, heat exchangers, and environments containing chlorides, acids, or H₂S
(NACE MR0175 / ISO 15156 and MR0103 / ISO 17495-1), providing a reliable technical solution for severe operating conditions.

Reference Standards and Certifications

The selection of seamless tube materials must always be supported by the relevant standards and certifications.
Specifications such as ASTM A269 and ASTM A213 are well-established references for industrial applications.

Internationally, tubes can be supplied in compliance with ASME, DIN, ISO, and EN standards.
For more critical environments, NORSOK and Saudi Aramco compliance is particularly relevant—standards for which we have supplied over €2 million in material and more than 200,000 meters of tubing.

Certifications such as PED and AD 2000 W2 confirm suitability for pressure equipment, while third-party approvals from organizations like TÜV and Lloyd’s Register provide additional assurance of quality and full traceability.

Material and Format: An Integrated Choice

The selection of seamless tube materials should always be evaluated together with the supply format—coils or bars.
Depending on the chosen alloy and the specific application, the correct combination of material and format helps simplify installation, improve reliability, and ensure full compliance with project specifications.

Contact us to identify the most suitable alloy for your plant and receive dedicated technical support.